The invention provides an innovative approach to calibrating displays. Prior art display calibration systems either required an expensive photometer, or were very subjective. Simple and objective calibration was a desired feature but unattainable in the prior art.
Examples of prior art techniques include U.S. Pat. Nos. 4,091,411; 4,914,506 and 4,101,928 which disclose methods for adjusting saturation and color hue that are unrelated to the subject invention except in a tangential manner.
Aldus Photostyler.TM. in an example of a personal computer application running under windows that has image enhancement features. Photostyler is a professional color image processing application for use with Microsoft.RTM. Windows. It includes a rudimentary display calibration feature for initializing the display prior to enhancing the images.
U.S. Pat. No. 4,106,846 discloses a mechanical device for unrolling a test pattern over a display screen to adjust color and intensity appropriately. The test pattern is unrolled from the mechanical device on a spring loaded roller that resembles a window shade.
U.S. Pat. No. 4,760,447 discloses a method for verifying the calibration of cameras for photographing images generated from electronic data. The camera is initially calibrated using optical densitometers to bring the camera into a preselected initial calibration. After the initial calibration, a calibration pattern is displayed and photographed to produce a reference photograph. The calibration pattern includes at least two brightness and contrast calibration regions, each region having a background and a plurality of subregions. In each region, the subregions each have progressively greater contrast with the background portion such that the number of visible subregions varies with brightness and contrast settings. The number of visible subregions of each calibration region is recorded. At a subsequent time, the calibration is again verified by displaying the same calibration pattern and comparing the number of visible subregions with the recorded numbers of visible subregions.
None of the prior art references teach an objective instrumentless display calibration system or method.